Method and apparatus for supporting supplementary uplink frequencies in next generation mobile communication system

ABSTRACT

The present disclosure relates to a communication scheme and system for converging a 5th generation (5G) communication system for supporting a data rate higher than that of a 4th generation (4G) system with an internet of things (IoT) technology. The present disclosure is applicable to intelligent services (e.g., smart home, smart building, smart city, smart car, connected car, health care, digital education, retail, and security and safety-related services) based on the 5G communication technology and the IoT-related technology. The present disclosure provides a method for preventing a legacy terminal from camping on an enhanced LTE (eLTE) base station that is connected to only a next generation (NG) core by combining a legacy information element (IE) and a new IE carried in system information broadcast by the base station in a next generation mobile communication system.

CROSS-REFERENCE TO RELATED APPLICATIONS

This application is a continuation of U.S. application Ser. No.16/101,303, filed Aug. 10, 2018, which is based on and claims priorityunder 35 U.S.C. § 119(a) to Korean Patent Application No.10-2017-0102623, filed on Aug. 11, 2017, in the Korean IntellectualProperty Office, the disclosure of which is incorporated by referenceherein in its entirety.

BACKGROUND 1. Field

The present disclosure relates to a method and apparatus for supportingsupplementary uplink frequencies between a terminal and a base stationin a next generation mobile communication system.

2. Description of Related Art

In order to meet the increasing demand for wireless data traffic sincethe commercialization of 4^(th) generation (4G) communication systems,the development focus is on the 5^(th) generation (5G) or pre-5Gcommunication system. For this reason, the 5G or pre-5G communicationsystem is called a beyond 4G network communication system or postlong-term evolution (LTE) system.

Implementation of the 5G communication system in millimeter wave(mmWave) frequency bands (e.g., 60 GHz bands) is being considered toaccomplish higher data rates. In order to increase the propagationdistance by mitigating propagation loss in the 5G communication system,discussions are underway about various techniques such as beamforming,massive multiple-input multiple output (MIMO), full dimensional MIMO(FD-MIMO), array antenna, analog beamforming, and large-scale antenna.

Also, in order to enhance network performance of the 5G communicationsystem, developments are underway of various techniques such as evolvedsmall cell, advanced small cell, cloud radio access network (RAN),ultra-dense network, device-to-device (D2D) communication, wirelessbackhaul, moving network, cooperative communication, coordinatedmulti-points (CoMP), and interference cancellation.

Furthermore, the ongoing research includes the use of hybrid frequencyshift keying (FSK) and quadrature amplitude modulation (QAM) {FOAM} andsliding window superposition coding (SWSC) as advanced coding modulation(ACM), filter bank multi-carrier (FBMC), non-orthogonal multiple access(NOMA), and sparse code multiple access (SCMA).

Meanwhile, the Internet is evolving from a human-centric communicationnetwork in which information is generated and consumed by humans to theInternet of things (IoT) in which distributed things or componentsexchange and process information. The combination of the cloudserver-based Big data processing technology and the IoT begets Internetof everything (IoE) technology. In order to secure the sensingtechnology, wired/wireless communication and network infrastructure,service interface technology, and security technology required forimplementing the IoT, recent research has focused on sensor network,machine-to-machine (M2M), and machine-type communication (MTC)technologies.

In the IoT environment, it is possible to provide an intelligentInternet Technology that is capable of collecting and analyzing datagenerated from connected things to create new values for human life. TheIoT can be applied to various fields such as smart home, smart building,smart city, smart car or connected car, smart grid, health care, smartappliance, and smart medical service through legacy informationtechnology (IT) and convergence of various industries.

Thus, there are various attempts to apply the IoT to the 5Gcommunication system. For example, the sensor network, M2M, and MTCtechnologies are implemented by means of the 5G communicationtechnologies such as beamforming, MIMO, and array antenna. Theapplication of the aforementioned cloud RAN as a big data processingtechnology is an example of convergence between the 5G and IoTtechnologies.

Typically, in a mobile communication system, there is a coveragemismatch between downlink (DL) and uplink (UL), i.e., a DL coverage isbroader than an UL coverage, and in order to overcome this coveragemismatch problem, the effective DL coverage is reduced in size formatching with the UL coverage. In this respect, in the next generationmobile communication system there is a need of a method and apparatusfor enabling a terminal to use a UL frequency for broader coveragewithout such performance limitation.

SUMMARY

The present disclosure aims to provide a method for allowing a terminalto use a UL frequency for better service coverage to overcome theperformance limitation caused by a UL-DL coverage mismatch that arisesfrom a maximum transmit power restriction of the terminal in a nextgeneration mobile communication system.

Also, the present disclosure aims to provide a method for preventing alegacy terminal from camping on an enhanced LTE (eLTE) base station thatis connected to only a next generation (NG) core by combining a legacyinformation element (IE) and a new IE carried in system informationbroadcast by the base station in a next generation mobile communicationsystem.

In accordance with an aspect of the present disclosure, a method foroperating a base station capable of communicating with at least one of afirst core network and a second core network in a wireless communicationsystem comprises generating first information indicating whether a firsttype of terminal is barred from access to the base station and secondinformation indicating whether a second type of terminal is barred fromaccess to the base station, wherein the first type of terminal iscapable of communicating with the first core network, and the secondtype of terminal is capable of communicating with both the first corenetwork and the second core network; and transmitting a messageincluding the generated first and second information to at least oneterminal.

In accordance with another aspect of the present disclosure, a method bya terminal in a wireless communication system comprises identifyingwhether the terminal is a first type of terminal or a second type ofterminal, wherein the first type of terminal is capable of communicatingwith a first core network, and the second type of terminal is capable ofcommunicating with both the first core network and a second corenetwork; receiving, from a base station, a message including firstinformation indicating whether an access to the base station is barredfor the first type and second information indicating whether an accessto the base station is barred for the second type of terminal; anddetermining whether to access to the base station based on an identifiedtype of terminal and one of the first information or the secondinformation associated with the identified type of the terminal.

In accordance with still another aspect of the present disclosure, abase station capable of communicating with at least one of a first corenetwork and a second core network in a wireless communication system,comprises a transceiver configured to transmit and receive signals; anda controller configured to generating first information indicatingwhether a first type of terminal is barred from access to the basestation and second information indicating whether a second type isbarred from access to the base station, wherein the first type ofterminal is capable of communicating with the first core network, andthe second type of terminal is type capable of communicating with boththe first core network and the second core network; and transmitting,via the transceiver to at least one terminal, a message including thegenerated first and second information.

In accordance with yet still another aspect of the present disclosure, aterminal in a wireless communication system, comprises a transceiverconfigured to transmit and receive signals; and a controller configuredto: identifying whether a type of the terminal is a first type or asecond type, a terminal of the first type capable of communicating witha first core network, and a terminal of the second type capable ofcommunicating with both the first core network and a second corenetwork; receiving, via the transceiver from a base station, a messageincluding first information indicating whether an access to the basestation by the terminal of the first type is barred and secondinformation indicating whether an access to the base station by theterminal of the second type is barred; and determining whether to accessto the base station based on one of the first information and the secondinformation associated with the identified type of the terminal.

Before undertaking the DETAILED DESCRIPTION below, it may beadvantageous to set forth definitions of certain words and phrases usedthroughout this patent document: the terms “include” and “comprise,” aswell as derivatives thereof, mean inclusion without limitation; the term“or,” is inclusive, meaning and/or; the phrases “associated with” and“associated therewith,” as well as derivatives thereof, may mean toinclude, be included within, interconnect with, contain, be containedwithin, connect to or with, couple to or with, be communicable with,cooperate with, interleave, juxtapose, be proximate to, be bound to orwith, have, have a property of, or the like; and the term “controller”means any device, system or part thereof that controls at least oneoperation, such a device may be implemented in hardware, firmware orsoftware, or some combination of at least two of the same. It should benoted that the functionality associated with any particular controllermay be centralized or distributed, whether locally or remotely.

Moreover, various functions described below can be implemented orsupported by one or more computer programs, each of which is formed fromcomputer readable program code and embodied in a computer readablemedium. The terms “application” and “program” refer to one or morecomputer programs, software components, sets of instructions,procedures, functions, objects, classes, instances, related data, or aportion thereof adapted for implementation in a suitable computerreadable program code. The phrase “computer readable program code”includes any type of computer code, including source code, object code,and executable code. The phrase “computer readable medium” includes anytype of medium capable of being accessed by a computer, such as readonly memory (ROM), random access memory (RAM), a hard disk drive, acompact disc (CD), a digital video disc (DVD), or any other type ofmemory. A “non-transitory” computer readable medium excludes wired,wireless, optical, or other communication links that transporttransitory electrical or other signals. A non-transitory computerreadable medium includes media where data can be permanently stored andmedia where data can be stored and later overwritten, such as arewritable optical disc or an erasable memory device.

Definitions for certain words and phrases are provided throughout thispatent document, those of ordinary skill in the art should understandthat in many, if not most instances, such definitions apply to prior, aswell as future uses of such defined words and phrases.

BRIEF DESCRIPTION OF THE DRAWINGS

For a more complete understanding of the present disclosure and itsadvantages, reference is now made to the following description taken inconjunction with the accompanying drawings, in which like referencenumerals represent like parts:

FIG. 1A is an exemplary diagram illustrating architecture of a nextgeneration mobile communication system;

FIGS. 1BA-1BB are exemplary conceptual views for explainingsupplementary UL frequency that is employed in the embodiments of thepresent disclosure;

FIG. 1C is an exemplary conceptual diagram for explaining a method foruse of an supplementary UL frequency (SUL) frequency and an NR UL in anext generation mobile communication system according to an embodimentof the present disclosure;

FIG. 1D is a signal flow diagram illustrating a procedure for use of anSUL frequency and an NR UL frequency according to an embodiment of thepresent disclosure;

FIG. 1E is an exemplary flowchart illustrating operations of a UEaccording to an embodiment of the present disclosure;

FIG. 1F is an exemplary conceptual diagram for explaining a method foruse of an SUL frequency according to another embodiment of the presentdisclosure;

FIG. 1G is an exemplary block diagram illustrating a configuration of aUE according to an embodiment of the present disclosure;

FIG. 1H is an exemplary block diagram illustrating a configuration of agNB according to an embodiment of the present disclosure;

FIG. 2A is an exemplary diagram illustrating a next generation mobilecommunication network to which an LTE eNB is connected;

FIG. 2B is a signal flow diagram illustrating a procedure of prohibitingaccess of UEs that are not supported by a next generation mobilecommunication network according to an embodiment of the presentdisclosure;

FIG. 2C is a signal flow diagram illustrating a procedure of prohibitingaccess of a UE being supported by a next generation mobile communicationsystem according to an embodiment of the present disclosure;

FIG. 2D is an exemplary flowchart illustrating an operation of a UE in anext generation mobile communication system according to an embodimentof the present disclosure;

FIG. 2E is an exemplary block diagram illustrating a configuration of aUE according to an embodiment of the present disclosure; and

FIG. 2F is an exemplary block diagram illustrating a configuration of agNB according to an embodiment of the present disclosure.

DETAILED DESCRIPTION

FIGS. 1A through 2F, discussed below, and the various embodiments usedto describe the principles of the present disclosure in this patentdocument are by way of illustration only and should not be construed inany way to limit the scope of the disclosure. Those skilled in the artwill understand that the principles of the present disclosure may beimplemented in any suitably arranged system or device

Exemplary embodiments of the present disclosure are described in detailwith reference to the accompanying drawings. Detailed descriptions ofwell-known functions and structures incorporated herein may be omittedto avoid obscuring the subject matter of the present disclosure.Further, the following terms are defined in consideration of thefunctionality in the present disclosure, and they may vary according tothe intention of a user or an operator, usage, etc. Therefore, thedefinition should be made on the basis of the overall content of thepresent specification.

Advantages and features of the present disclosure and methods ofaccomplishing the same may be understood more readily by reference tothe following detailed description of exemplary embodiments and theaccompanying drawings. The present disclosure may, however, be embodiedin many different forms and should not be construed as being limited tothe exemplary embodiments set forth herein. Rather, these exemplaryembodiments are provided so that this disclosure will be thorough andcomplete and will fully convey the concept of the disclosure to thoseskilled in the art, and the present disclosure will only be defined bythe appended claims. Like reference numerals refer to like elementsthroughout the specification.

First Embodiment

FIG. 1A is an exemplary diagram illustrating an exemplary architectureof a next generation mobile communication system.

In reference to FIG. 1A, a radio access network of the next generationmobile communication system includes a new radio node B (hereinafter,interchangeably referred to as NR NB) 1 a-10 and a new radio corenetwork (NR CN) 1 a-05. A new radio user equipment (NR UE) 1 a-15(hereinafter, interchangeably referred to as terminal) accesses anexternal network via the NR NB 1 a-10 and the NR CN 1 a-05.

In FIG. 1A, the NR NB 1 a-10 corresponds to an evolved node B (eNB) of alegacy LTE system. The NR UE 1 a-15 connects to the NR NB 1 a-10, whichprovides more sophisticated service in comparison with the legacy eNB.In the next generation mobile communication system where all usertraffic is served through shared channels, there is a need of an entityfor collecting UE-specific status information (such as buffer status,power headroom status, and channel status) and scheduling the UEs basedon the collected information, and the NR NB 1 a-10 takes charge of suchfunctions.

Typically, one NR NB hosts multiple cells. In order to meet the datarate requirement that is higher than that for legacy LTE, it isnecessary to secure a maximum bandwidth broader than ever before byemploying advanced technologies such as orthogonal frequency divisionmultiplexing (OFDM) as a radio access scheme and beamforming. It may bepossible to employ an adoptive modulation and coding (AMC) technology todetermine a modulation scheme and a channel coding rate in adaptation tothe channel condition of the UE.

The NR CN 1 a-05 is responsible for mobility management, bearer setup,and QoS setup. The NR CN 1 a-05 is responsible for other controlfunctions as well as UE mobility management functions in connection witha plurality of NR NBs. The next generation mobile communication systemmay interoperate with legacy LTE systems in such a way as to connect theNR CN 1 a-05 to a mobility management entity (MME) 1 a-25 through anetwork interface. The MME 1 a-25 is connected to an eNB 1 a-30 as alegacy base station.

FIG. 1BA-1BB illustrate exemplary embodiments utilizing a supplementaryUL frequency that is employed in the embodiments of the presentdisclosure.

In a mobile communication system, a UL-DL coverage mismatch may occur.The UL-DL coverage mismatch occurs because of a difference in channelcharacteristics between UL and DL or a limitation of the maximumtransmit power of a terminal. In an exemplary case of a 3.5 GHz TDDsystem, the DL coverage 1 b-05 is broader than the UL coverage 1 b-10.

In this case, there is no problem in that a first UE 1 b-20 receivesservices in both the UL and DL, but a problem may occur in that thesecond UE 1 b-25 transmits UL data to the gNB 1 b-15. In order tomitigate the problem that arises from such coverage mismatch, theeffective DL coverage is reduced in size for matching with the ULcoverage. That is, although a wider service area can be provided in thedownlink, the service area of the downlink is limited to a service areaof the uplink.

In the next generation mobile communication system, a method is employedfor a UE to use a UL frequency for broader coverage to overcome theperformance limitation that arises from such mismatch. That is, the UEis capable of using a supplementary UL frequency of 1.8 GHz in additionto the UL frequency of 3.5 GHz as denoted by reference number of 1 b-30.The supplementary UL frequency is referred to as SUL frequency. By thenature of frequency, the propagation distance of a radio signalincreases as the frequency decreases. This means that a frequency of 1.8GHz that is lower than the frequency of 3.5 GHz expands the coverage. Asa consequence, the second UE 1 b-50 is capable of transmitting data tothe gNB 1 b-40 successfully using the UL frequency of 1.8 GHz as denotedby reference number 1 b-30.

Regardless of the coverage issue, the first UE 1 b-45 may select one ofthe 1.8 GHz frequency band or the 3.5 GHz frequency band for the purposeof distributing UL access congestion because it can use both the 1.8 GHzand 3.5 GHz UL frequency bands. The SUL frequency may be an LTEfrequency.

In the case where a UE uses one of the SUL frequency and the NR ULfrequency, there is a need of an operation for switching from the NR ULfrequency to the SUL frequency at an NR UL coverage boundary. This mayincrease signaling overhead and cause a service breakdown. There istherefore a need of minimizing the number of UL frequency switchingoperations.

The present disclosure provides a method for using the NR UL frequencyin the NR UL coverage area in which the SUL frequency is regarded as thedefault UL frequency.

FIG. 1C is an exemplary conceptual diagram for illustrating an exemplarymethod for use of an SUL frequency and an NR UL in a next generationmobile communication system according to an embodiment of the presentdisclosure.

The SUL frequency may provide a UL coverage similar in size to the DLcoverage. For example, the SUL frequency of 1.8 GHz provides a ULcoverage similar to that of the NR DL frequency of 3.5 GHz. Meanwhile,the NR UL frequency of 3.5 GHz cannot provide sufficient coverage.

The present disclosure may be characterized in that a UE performs arandom access on an SUL frequency to transmit at least a physical uplinkcontrol channel (PUCCH). The SUL frequency is also used as a defaultfrequency for transmitting a physical uplink shared channel (PUSCH) and,in response to a UE's request or gNB's command, it may be possible touse the NR UL frequency in addition to or instead of the SUL frequencyfor the PUSCH (data) transmission.

FIG. 1D is a signal flow diagram illustrating a procedure for use of aSUL frequency and an NR UL frequency according to an embodiment of thepresent disclosure.

At step 1 d-15, a gNB 1 d-10 supporting the SUL frequency broadcastssystem information including SUL frequency-specific random accesschannel (RACH) configuration information for use by the UEs locatedwithin its coverage. The system information may further includeinformation on maximum transmit power value P_max required on the NR ULfrequency and SUL frequency. A UE 1 d-05 may determine whether it islocated within the frequency-specific coverages based on the value ofP_max.

The UE 1 d-05 triggers an access at step 1 d-20. The UE 1 d-05 performsa random access on the SUL frequency at step 1 d-25. The UE 1 d-05transits PUCCH and PUSCH on the SUL frequency at step 1 d-30.

According to a request generated by the gNB 1 d-10 or the UE 1 d-05, thegNB 1 d-10 determines to use the NR UL frequency for PUSCH transmissionat step 1 d-35. This determination may be made by the gNB 1 d-10 basedon a cell-specific measurement information or buffer status report(BSR). This determination may be made by the UE 1 d-05 when a UE'smaximum transmit power (P_powerclass) value is greater than the P_maxfor the NR UL and, in this case, the UE 1 d-05 may report thedetermination result to the gNB 1 d-10. If the above condition isfulfilled, this means that the UE 1 d-05 is located within the NR ULcoverage.

The gNB 1 d-10 transmits PUSCH configuration information for the NR ULto the UE 1 d-05 at step 1 d-40. The configuration information mayinclude NR UL frequency information and an indication instructing the UE1 d-05 to perform random access. The configuration information mayinclude an indication instructing the UE 1 d-05 to perform random accesswith a PDCCH order. The PDCCH order may include the NR UL frequencyinformation and RACH configuration information.

After completing the random access, the UE 1 d-05 transmits PUSCH on theNR UL at step 1 d-45. The random access operation may be omitted.However, the PUCCH is still transmitted on the SUL frequency. In thepresent disclosure, the RACH configuration information denotes physicalrandom access channel (PRACH) radio resource information, preambleinformation, and preamble transmit power information.

FIG. 1E is an exemplary flowchart illustrating an operation of a UEaccording to an embodiment of the present disclosure.

At step 1 e-05, the UE receives RACH configuration information for anSUL frequency via system information broadcast by a gNB. At step 1 e-10,the UE triggers an access. The UE performs a random access on the SULfrequency. At step 1 e-20, the UE transmits both the PUCCH and PUSCH onthe SUL frequency.

At step 1 e-25, the UE receives, from the gNB, an instruction to add orswitch to an NR UL for PUSCH transmission. This instruction is carriedby a radio resource control (RRC) connection reconfiguration messageincluding PUSCH configuration information, information on whether toperform a random access, and NR UL frequency information. In order toinstruct to perform the random access, a PDCCH order is separately used.The PDCCH order includes the NR UL frequency information and RACHconfiguration information.

At step 1 e-30, the UE performs a random access on the NR UL. The randomaccess operation may be omitted. At step 1 e-35, the UE transmits thePUSCH on the NR UL after completing the random access.

FIG. 1F is an exemplary conceptual diagram for illustrating an exemplarymethod for use of an SUL frequency according to another embodiment ofthe present disclosure.

It may be possible to design the UL and DL coverages to be matched usingthe NR frequency. However, there may be still a weak signal strengtharea such as a basement and a subway. In such an area, the UL signal islikely to be much weaker. Accordingly, it is preferred to use the SULfrequency for UL transmission in such an area.

In such a scenario, the NR UL frequency is used as a default ULfrequency for PUCCH and PUSCH transmission, while the SUL frequency isused for PUCCH and PUSCH transmission in the weak UL signal strengtharea. However, the SUL frequency may be used for PUSCH transmissionbecause the PUCCH can be in the weak signal strength area by nature ofits robust reception performance in comparison with PUSCH. In thisscenario, the roles of the SUL and NR UL frequencies are opposite tothose in FIGS. 1D and 1E. If the PUSCH reception performance drops in acertain area while transmitting PUCCH and PUSCH on the NR UL, the gNBconfigures to the UE to transmit the PUSCH on the SUL frequency. Thisconfiguration may be performed via the PDCCH order, which includes theSUL frequency information and RACH configuration information.

FIG. 1G is an exemplary block diagram illustrating a configuration of aUE according to an embodiment of the present disclosure.

In reference to FIG. 1G, the UE includes a radio frequency (RF)processor 1 g-10, a baseband processor 1 g-20, a storage unit 1 g-30,and a controller 1 g-40.

The RF processor 1 g-10 has a function for transmitting/receiving asignal over a radio channel such as band conversion and amplification ofthe signal. That is, the RF processor 1 g-10 up-converts a basebandsignal from the baseband processor 1 g-20 to an RF band signal andtransmits the RF signal via an antenna and down-converts the RF signalreceived via the antenna to a baseband signal. For example, the RFprocessor 1 g-10 may include a transmission filter, a reception filter,an amplifier, a mixer, an oscillator, a digital-to-analog converter(DAC), and an analog-to-digital converter (ADC).

Although one antenna is depicted in the drawing, the UE may be providedwith a plurality of antennas. The RF processor 1 g-10 may also include aplurality of RF chains. The RF processor 1 g-10 may perform beamforming.For beamforming, the RF processor 1 g-10 may adjust the phase and sizeof a signal to be transmitted/received by means of the antennas orantenna elements in phase and size. The RF processor 1 g-1—may beconfigured to support a MIMO scheme with which the UE can receivemultiple layers simultaneously

The baseband processor 1 g-20 has a baseband signal-bit stringconversion function according to a physical layer standard of thesystem. For example, in a data transmission mode, the baseband processor1 g-20 performs encoding and modulation on the transmission bit stringto generate complex symbols. In a data reception mode, the basebandprocessor 1 g-20 performs demodulation and decoding on the basebandsignal from the RF processor 1 g-10 to recover the transmitted bitstring. In the case of using an OFDM scheme for data transmission, thebaseband processor 1 g-20 performs encoding and modulation on thetransmission bit string to generate complex symbols, maps the complexsymbols to subcarriers, performs inverse fast Fourier transform (IFFT)on the symbols, and inserts a cyclic prefix (CP) into the symbols togenerate OFDM symbols.

In the data reception mode, the baseband processor 1 g-20 splits thebaseband signal from the RF processor 1 g-10 into OFDM symbols, performsfast Fourier transform (FFT) on the OFDM symbols to recover the signalsmapped to the subcarriers, and performs demodulation and decoding on thesignals to recover the transmitted bit string.

The baseband processor 1 g-20 and the RF processor 1 g-10 process thetransmission and reception signals as described above. Accordingly, thebaseband processor 1 g-20 and the RF processor 1 g-10 may be referred toas a transmitter, a receiver, a transceiver, or a communication unit. Atleast one of the baseband processor 1 g-20 and the RF processor 1 g-10may include a plurality of communication modules for supportingdifferent radio access technologies.

At least one of the baseband processor 1 g-20 and the RF processor 1g-10 may also include multiple communication modules for processing thesignals in different frequency bands. For example, the different radioaccess technologies may include a wireless local area network (WLAN)(e.g., Institute of Electrical and Electronics Engineers (IEEE) 802.11)and a cellular network (e.g., LTE). The different frequency bands mayinclude a super high frequency (SHF) band (e.g., 2. NRHz and NRhz bands)and an mmWave band (e.g., 60 GHz).

The storage unit 1 g-30 stores data such as basic programs for operationof the UE, application programs, and setting information. The storageunit 1 g-30 may also store the information on a second access node forradio communication with a second radio access technology. The storageunit 1 g-30 provides the stored information in response to a requestfrom the controller 1 g-40.

The controller 1 g-40 controls overall operations of the UE. Forexample, the controller 1 g-40 controls the baseband processor 1 g-20and the RF processor 1 g-10 for transmitting and receiving signals. Thecontroller 1 g-40 writes and reads data to and from the storage unit 1g-40. For this purpose, the controller 1 g-40 may include at least oneprocessor. For example, the controller 1 g-40 may include acommunication processor (CP) for controlling communications and anapplication processor (AP) for controlling higher layer programs such asapplications.

FIG. 1H is an exemplary block diagram illustrating a configuration ofgNB according to an embodiment of the present disclosure.

In reference to FIG. 1H, the gNB includes an RF processor 1 h-10, abaseband processor 1 h-20, a backhaul communication unit 1 h-30, astorage unit 1 h-40, and a controller 1 h-50.

The RF processor 1 h-10 has a function for transmitting/receiving asignal over a radio channel such as band conversion and amplification ofthe signal. That is, the RF processor 1 h-10 up-converts a basebandsignal from the baseband processor 1 h-20 to an RF band signal andtransmits the RF signal via an antenna and down-converts the RF signalreceived via the antenna to a baseband signal. For example, the RFprocessor 1 h-10 may include a transmission filter, a reception filter,an amplifier, a mixer, an oscillator, a DAC, and an ADC.

Although one antenna is depicted in the drawing, the gNB may be providedwith a plurality of antennas. The RF processor 1 h-10 may also include aplurality of RF chains. The RF processor 1 i-10 may perform beamforming.For beamforming, the RF processor 1 h-10 may adjust the phase and sizeof a signal to be transmitted/received by means of the antennas orantenna elements. The RF processor 1 h-10 may be configured to transmitone or more layers for a downlink MIMO operation.

The baseband processor 1 h-20 has a baseband signal-bit stringconversion function according to a physical layer standard of thesystem. For example, in a data transmission mode, the baseband processor1 h-20 performs encoding and modulation on the transmission bit stringto generate complex symbols. In a data reception mode, the basebandprocessor 1 h-20 performs demodulation and decoding on the basebandsignal from the RF processor 1 h-10 to recover the transmitted bitstring. In the case of using an OFDM scheme for data transmission, thebaseband processor 1 h-20 performs encoding and modulation on thetransmission bit string to generate complex symbols, maps the complexsymbols to subcarriers, performs inverse fast Fourier transform (IFFT)on the symbols, and inserts a cyclic prefix (CP) into the symbols togenerate OFDM symbols.

In the data reception mode, the baseband processor 1 h-20 splits thebaseband signal from the RF processor 1 h-10 into OFDM symbols, performsfast Fourier transform (FFT) on the OFDM symbols to recover the signalsmapped to the subcarriers, and performs demodulation and decoding on thesignals to recover the transmitted bit string. The baseband processor 1h-20 and the RF processor 1 h-10 process the transmission and receptionsignals as described above. Accordingly, the baseband processor 1 h-20and the RF processor 1 h-10 may be referred to as a transmitter, areceiver, a transceiver, or a communication unit.

The backhaul communication unit 1 h-30 provides an interface forcommunication with other nodes in the network. That is, the backhaulcommunication unit 1 h-30 converts a bit string to be transmitted fromthe gNB to another node, e.g., another gNB and core network, to aphysical signal and converts a physical signal received from anothernode to a bit string.

The storage unit 1 h-40 stores data such as basic programs for operationof the gNB, application programs, and setting information. The storageunit 1 h-40 may also store the information on the bearers establishedfor UEs and measurement results reported by the connected UEs. Thestorage unit 1 h-40 may also store the information for use by a UE indetermining whether to enable or disable multi-connectivity. The storageunit 1 h-40 may provide the stored data in reference to a request fromthe controller 1 h-50.

The controller 1 h-50 controls overall operations of the gNB. Forexample, the controller 1 h-50 controls the baseband processor 1 h-20,the RF processor 1 h-10, and the backhaul communication unit 1 h-30 fortransmitting and receiving signals. The controller 1 h-50 writes andreads data to and from the storage unit 1 h-40. For this purpose, thecontroller 1 h-50 may include at least one processor.

Second Embodiment

FIG. 2A is an exemplary diagram illustrating a next generation mobilecommunication network to which an LTE eNB is connected according toembodiments of the present disclosure.

A legacy LTE eNB 2 a-15 connects to a mobility management entity (MME) 2a-05 as a network entity. It may be possible to upgrade a legacy LTE eNBsuch that the upgraded LTE eNB, as well as a next generation mobilecommunication base station, can connect to the next generation mobilecommunication network (NG core) 2 a-10. The upgraded LTE eNB is referredto as evolved/enhanced LTE (eLTE) eNB 2 a-20.

The eLTE eNB 2 a-20 may connect to one or both of the legacy MME or nextgeneration mobile communication network. If the eLTE eNB 2 a-20 is onlyconnected to the NG core, only an eLTE UE 2 a-30 can connect to the eLTEeNB 2 a-20 to communicate with the next generation mobile communicationnetwork. Meanwhile, although a legacy UE 2 a-25 attempts to access tothe eLTE eNB 2 a-20, it cannot communicate with the next generationmobile communication network. Accordingly, it is necessary to preventthe legacy UE 2 a-25 from remaining camped on the eLTE eNB 2 a-20connected only to the NG core 2 a-10.

The present disclosure proposes a method for preventing a legacy LTE UEfrom camping on an eLTE eNB connected only to an NG core using acombination of a legacy IE and a new IE in the system informationbroadcast by the LTE eNB.

Table 1 shows the ASN.1 for system information block (SIB) 1 specifiedfor the legacy LTE technology. In the present disclosure, new IEs areincluded in the SIB 1.

TABLE 1 SystemInformationBlockType1 message -- ASN1STARTSystemInformationBlockType1-BR-r13 ::= SystemInformationBlockType1SystemInformationBlockType1 ::= SEQUENCE {  cellAccessRelatedInfo SEQUENCE {   plmn-IdentityList   PLMN-IdentityList,   trackingAreaCode  TrackingAreaCode,   cellIdentity   CellIdentity,   cellBarred  ENUMERATED {barred, notBarred},   intraFreqReselection   ENUMERATED{allowed, notAllowed},   csg-Indication   BOOLEAN,   csg-Identity  CSG-Identity       OPTIONAL -- Need OR  },  cellSelectionInfo SEQUENCE {   q-RxLevMin   Q-RxLevMin,   q-RxLevMinOffset   INTEGER(1..8)      OPTIONAL -- Need OP  },  p-Max  P-Max           OPTIONAL, -- Need OP  freqBandIndicator  FreqBandIndicator,  schedulingInfoList SchedulingInfoList,  tdd-Config  TDD-Config         OPTIONAL, -- CondTDD  si-WindowLength  ENUMERATED {   ms1, ms2, ms5, ms10, ms15, ms20,  ms40},  systemInfoValueTag  INTEGER {0..31},  nonCriticalExtension SystemInformationBlockType1-v890-IEs OPTIONAL }SystemInformationBlockType1-v890-IEs::= SEQUENCE { lateNonCriticalExtension  OCTET STRING (CONTAININGSystemInformationBlockTypel- v8h0-IEs)   OPTIONAL,  nonCriticalExtensionSystemInformationBlockType1-v920-IEs OPTIONAL } -- Late non criticalextensions SystemInformationBlockType1-v8h0-IEs ::= SEQUENCE { multiBandInfoList MultiBandInfoList         OPTIONAL, -- Need OR nonCriticalExtension SystemInformationBlockType1-v9e0-IEs OPTIONAL }SystemInformationBlockType1-v9e0-IEs ::= SEQUENCE { freqBandIndicator-v9e0 FreqBandIndicator-v9e0         OPTIONAL, -- CondFBI- max  multiBandInfoList-v9e0MultiBandInfoList-v9e0         OPTIONAL, -- Cond mFBI- max nonCriticalExtension SystemInformationBlockType1-v10j0-IEs OPTIONAL }SystemInformationBlockType1-v10j0-IEs ::= SEQUENCE {  freqBandInfo-r10NS-PmaxList-r10            OPTIONAL, -- Need OR  multiBandInfoList-v10j0MultiBandInfoList-v10j0         OPTIONAL, -- Need OR nonCriticalExtension SEQUENCE { }             OPTIONAL } -- Regular noncritical extensions SystemInformationBlockType1-v920-IEs ::= SEQUENCE { ims-EmergencySupport-r9 ENUMERATED {true}        OPTIONAL, -- Need OR cellSelectionInfo-v920 CellSelectionInfo-v920         OPTIONAL, -- CondRSRQ  nonCriticalExtension SystemInformationBlockType1-v1130-IEsOPTIONAL } SystemInformationBlockType1-v1130-IEs ::= SEQUENCE { tdd-Config-v1130 TDD-Config-v1130          OPTIONAL, -- Cond TDD-OR cellSelectionInfo-v1130 CellSelectionInfo-v1130        OPTIONAL, --Cond WB-RSRQ  nonCriticalExtensionSystemInformationBlockType1-v1250-IEs     OPTIONAL }SystemInformationBlockType1-v1250-IEs ::= SEQUENCE { cellAccessRelatedInfo-v1250 SEQUENCE {   category0Allowed-r12 ENUMERATED {true}     OPTIONAL -- Need OP  },  cellSelectionInfo-v1250CellSelectionInfo-v1250         OPTIONAL, -- Cond RSRQ2 freqBandIndicatorPriority-r12 ENUMERATED {true}         OPTIONAL, --Cond mFBI  nonCriticalExtensionSystemInformationBlockType1-v1310-IEs         OPTIONAL }SystemInformationBlockType1-v1310-IEs ::= SEQUENCE {  hyperSFN-r13 BITSTRING (SIZE (10))         OPTIONAL, -- Need OR  eDRX-Allowed-r13ENUMERATED {true}          OPTIONAL, -- Need OR  cellSelectionInfoCE-r13CellSelectionInfoCE-r13 OPTIONAL,          -- Need OP bandwidthReducedAccessRelatedInfo-r13 SEQUENCE {  si-WindowLength-BR-r13  ENUMERATED {   ms20, ms40, ms60, ms80, ms120,  ms160, ms200, spare},   si-RepetitionPattern-r13  ENUMERATED {everyRF,every2ndRF, every4thRF,    every8thRF},   schedulingInfoList-BR-r13 SchedulingInfoList-BR-r13          OPTIONAL, -- Need OR  fdd-DownlinkOrTddSubframeBitmapBR-r13  CHOICE {   subframePattern10-r13   BIT STRING (SIZE (10)),   subframePattern40-r13   BIT STRING (SIZE (40))   }                       OPTIONAL, -- Need OP  fdd-UplinkSubframeBitmapBR-r13  BIT STRING (SIZE(10))           OPTIONAL, -- Need OP   startSymbolBR-r13  INTEGER(1..4),   si-HoppingConfigCommon-r13  ENUMERATED {on, off},  si-ValidityTime-r13  ENUMERATED {true}            OPTIONAL, -- Need OP  systemInfoValueTagList-r13 SystemInfoValueTagList-r13          OPTIONAL, -- Need OR  }                          OPTIONAL, -- Cond BW- reduced nonCriticalExtension  SystemInformationBlockTypel-v1320-IEs  OPTIONAL }SystemInformationBlockType1-v1320-IEs ::= SEQUENCE { fregHoppingParametersDL-r13 SEQUENCE {   mpdcch-pdsch-HoppingNB-r13 ENUMERATED {nb2, nb4}          OPTIONAL, -- Need OR  interval-DLHoppingConfigCommonModeA-r13 CHOICE {    interval-FDD-r13 ENUMERATED {intl, int2, int4, int8},    interval-TDD-r13  ENUMERATED{intl, int5, int10, int20}   }                        OPTIONAL, -- NeedOR   interval-DLHoppingConfigCommonModeB-r13 CHOICE {   interval-FDD-r13  ENUMERATED {int2, int4, int8, int16},   interval-TDD-r13  ENUMERATED {int5, int10, int20, int40}   }                       OPTIONAL, Need OR  mpdcch-pdsch-HoppingOffset-r13  INTEGER (1..maxAvailNarrowBands-r13) OPTIONAL -- Need OR  }                        OPTIONAL, -- Cond Hopping nonCriticalExtension  SystemInformationBlockTypel-v1350-IEs    OPTIONAL } SystemInformationBlockTypel-v1350-IEs ::=SEQUENCE { cellSelectionInfoCE1-r13 CellSelectionInfoCE1-r13             OPTIONAL,-- Need OP  nonCriticalExtension SystemInformationBlockTypel-v14xy-IEs  OPTIONAL } SystemInformationBlockTypel-v14xy-IEs ::= SEQUENCE { eCallOverIMS-Support-r14 ENUMERATED {true}              OPTIONAL, --Need OR  tdd-Config-v14xy TDD-Config-v14xy                OPTIONAL, --Cond TDD-OR  nonCriticalExtension SEQUENCE { }                 OPTIONAL} SystemInformatEonBlockTypel-v15xx-IEs ::= SEQUENCE {  cellBarred-r15ENUMERATED {barred, notBarred},  plmn-IdentityListPLMN-IdentityList5GCN,  nonCriticalExtension SEQUENCE { } OPTIONALPLMN-IdentityList ::=  SEQUENCE (SIZE (1..maxPLMN-r11)) OFPLMN-IdentityInfo PLMN-IdentityInfo ::=  SEQUENCE {  plmn-Identity  PLMN-Identity,  cellReservedForOperatorUse   ENUMERATED {reserved,notReserved} } PLMN-IdentityList5GCN ::=SEQUENCE(SIZE(1..maxPLMN-r11))OF PLMN-IdentityInfo5GCN PLMN-IdentityInfo5GCN ::=SEQUENCE { plmn-Identity PLMN-Identity,  cellReservedForOperatorUse ENUMERATE{reserved,notReserved},  cnType ENUMERATED {EPC,5GCN} SchedulingInfoList::= SEQUENCE (SIZE (1..maxSI-Message)) OF SchedulingInfo SchedulingInfo::= SEQUENCE {  si-Periodicity   ENUMERATED {    rf8, rf16, rf32, rf64,rf128, rf256, rf5121,  sib-MappingInfo   SIB-MappingInfo }SchedulingInfoList-BR-r13 ::= SEQUENCE (SIZE (1..maxSI-Message)) OFSchedulingInfo-BR-r13 SchedulingInfo-BR-r13 ::= SEQUENCE { si-Narrowband-r13  INTEGER (1..maxAvailNarrowBands-r13),  si-TBS-r13 ENUMERATED {b152, b208, b256, b328, b408, b504, b600, b712,    b808,b936} } SIB-MappingInfo ::= SEQUENCE (SIZE (0..maxSIB-1)) OF SIB-TypeSIB-Type ::= ENUMERATED {  sibType3, sibType4, sibType5, sibType6, sibType7, sibType8, sibType9, sibType10,  sibType11, sibType12-v920,sibType13-v920,  sibType14-v1130, sibType15-v1130,  sibType16-v1130,sibType17-v1250, sibType18-v1250,  . . . , sibType19-v1250,sibType20-v1310, sibType21- v14x0} SystemInfoValueTagList-r13 ::=SEQUENCE (SIZE (1..maxSI-Message)) OF SystemInfoValueTagSI-r13SystemInfoValueTagSI-r13 ::= INTEGER (0..3) CellSelectionInfo-v920 ::=SEQUENCE {  q-QualMin-r9  Q-QualMin-r9,  q-QualMinOffset-r9  INTEGER(1..8)             OPTIONAL -- Need OP } CellSelectionInfo-v1130 ::=SEQUENCE {  q-QualMinWB-r11  Q-QualMin-r9 } CellSelectionInfo-v1250 ::=SEQUENCE {  q-QualMinRSRQ-OnAllSymbols-r12         Q-QualMin-r9 } --ASN1STOP

If the eNB that broadcasts the SIB1 is an eLTE eNB connected only to theNG core, the legacy cellBarred IE is set to ‘barred’ in the SIB 1. Thisprohibits the legacy UEs from camping on the corresponding cell. Thelegacy UEs can understand only the legacy IEs including the cellBarredIE for use in prohibiting camping-on to the corresponding network. Ifthe legacy cellBarred IE is set to ‘barred,’ even the emergency callservice access is denied by the corresponding cell.

The eLTE eNB connected only to the NG core broadcasts newly specifiedcellBarred-r15 IE and plmn-IdentityList5GCN IE to support the eLTE UEs.The cell-Barred-r15 IE is configured for the purpose of prohibiting theeLTE UEs supported by the eLTE eNB connected only to the NG core fromaccess or camp-on to the eLTE eNB, and the plmn-IdentityList5GCN isconfigured for the purpose of providing NG core-related public landmobile network (PLMN) information.

An eLTE eNB connected to both the MME and NG core may support both thelegacy and eLTE UEs. The legacy cellBarred IE is set to ‘notBarred’ forany unusual purpose. The new cellBarred IE is also set to ‘notBarred.’Meanwhile, the eLTE eNB connected only to the NG core cannot support thelegacy UE but the eLTE UE. Accordingly, the legacy cellBarred IE is setto ‘barred.’ Also, the new cellBarred IE is set to ‘notBarred.’

The eLTE UE ascertains the type of the network supported by thecorresponding cell in consideration of the legacy plmn-IdentityList andthe newly-defined plmn-IdentityList5GCN. The PLMN IDs included in thelegacy plmn-IdentityList and newly-defined plmn-IdentityList5GCN IEs maybe identical with or different from each other. This is determined bythe operator.

The new PLMN configuration information may further include theinformation on the network entity, i.e., LTE MME or NG core entity, towhich the corresponding PLMN is connected. This aims to make it possiblefor the eLTE UE to select one of the MME or NG core.

The eLTE UE transmits to the MME a non-access stratum (NAS) messagegenerated in the legacy format and to the NG core the NAS messagegenerated in a new format in order for the MME and the NG core tounderstand the NAS message.

FIG. 2B is a signal flow diagram illustrating an exemplary procedure ofprohibiting access of UEs that are not supported by a next generationmobile communication network according to an embodiment of the presentdisclosure.

A legacy LTE UE 2 b-05 that cannot communicate with an NG core 2 b-15selects a PLMN, i.e., selected PLMN, on an NAS layer at step 2 b-20. Theselected PLMN is determined in consideration of a home PLMN (HPLMN) orHEPLMN recorded in a universal subscriber identity module (USIM). AneLTE eNB 2 b-10 is connected only to the NG core 2 b-15. Accordingly, atstep 2 b-30, the eLTE eNB 2 b-10 broadcasts the SIB1 including thecellBarred IE set to ‘barred’.

The legacy UEs that receive the SIB1 may not attempt to camp on thecorresponding cell. The legacy LTE UE 2 b-05 measures neighboring cellsand selects the eLTE cell with the best received signal strength at stepS2 b-25. Next, the legacy LTE UE 2 b-05 receives the system informationbroadcast via the corresponding cell at step 2 b-30. Since thecellBarred IE included in the SIB1 is set to ‘barred’, the legacy LTE UE2 b-05 assumes that its access to the corresponding cell is barred anddoes not attempt to camp on the corresponding cell at step 2 b-35. Theaccess barring for a UE is released after a predetermined time. Thelegacy LTE UE 2 b-05 searches for another cell at step 2 b-40.

FIG. 2C is a signal flow diagram illustrating an exemplary procedure ofprohibiting access of a UE being supported by a next generation mobilecommunication system according to an embodiment of the presentdisclosure.

An eLTE UE 2 c-05 that is capable of communicating with an NG core 2c-15 selects a PLMN, i.e., selected PLMN, on a NAS layer at step 2 c-20.The selected PLMN is determined in consideration of a home PLMN (HPLMN)or HEPLMN recorded in a USIM. An eLTE eNB 2 c-10 is connected only tothe NG core 2 c-15. Accordingly, at step 2 c-30, the eLTE eNB 2 c-10broadcasts the SIB1 including the cellBarred IE set to ‘barred.’ Thelegacy UEs that receives the SIB1 may not attempt to camp on thecorresponding cell.

The eLTE eNB 2 c-10 may also set the new cellBarred-r15 IE to‘notBarred’ in order for the eLTE UEs still to camp on the correspondingcell. In order to bar access of the eLTE UEs to the corresponding cell,the IE cellBarred-r15 IE is set to ‘barred.’ The eLTE UE 2 c-05 measuresneighboring cells and selects an eLTE cell with the best signal strengthat step 2 c-25. Next, the eLTE UE 2 c-20 receives the system informationbroadcast via the corresponding cell at step 2 c-30. Since thecellBarred IE is set to ‘barred’ and the cellBarred-r15 IE is set to‘notBarred’ in the SIB1, the eLTE UE 2 c-05 camps on the correspondingcell at step 2 c-35.

If at least one of the cellBarred IE and the cellBarred-r15 IE is set to‘notBarred’, the eLTE assumes that its access to the corresponding cellis not barred. If the new IE is not configured, the procedure should beperformed based on only the configuration information of the legacy IE.The access barring for a UE is released after a predetermined time. TheeLTE UE 2 c-05 performs a setup for communication with the NG core 2c-40.

At step 2 c-45, the eLTE UE 2 c-05 transmits to the NG core 2 c-15 anAttach Request message including the information on the selected PLMN.The selected PLMN should be included in the newly introducedplmn-IdentityList5GCN for access to usual services. Otherwise, onlylimited services such an emergency call service, are allowed for the UEto access via the corresponding cell. At step 2 c-50, the NG core 2 c-15transmits to the UE 2 c-05 an Attach Accept message including an ePLMNlist. Here, the selected PLMN is regarded as a registered PLMN.

FIG. 2D is an exemplary flowchart illustrating an exemplary operation ofa UE in a next generation mobile communication system according to anembodiment of the present disclosure.

At step 2 d-05, a UE NAS layer selects a PLMN, i.e., selected PLMN. Theselected PLMN is determined in consideration of the HPLMN or HEPLMNregistered in a USIM. At step 2 d-10, the UE selects a cell with asignal quality better than a predetermined level or a highest signalquality among the cells supporting the selected PLMN.

At step 2 d-15, the UE receives the SIB1 via the selected cell. At step2 d-20, the UE determines whether the received SIB1 includes acellBarred-r15 IE. If it is determined that the received SIB1 includesthe cellBarred-r15 IE, the UE determines whether at least one of thecellBarred IE and the cellBarred-r15 included in the SIB1 is set to‘notBarred’. If at least one of the cellBarred IE and the cellBarred-r15is set to ‘notBarred’, the UE assumes at step 2 d-30 that its access tothe corresponding cell is not barred. If neither the cellBarred IE northe cellBarred-r15 is set to ‘notBarred’, the UE assumes at step 2 d-35that its access to the corresponding cell is barred.

If it is determined that the received SIB1 includes no cellBarred-r15IE, the UE determines at step 2 d-40 whether the cellBarred IE is set to‘notBarred’. If it is determined that the cellBarred IE is set to‘notBarred’, the UE assumes at step 2 d-45 that its access to thecorresponding cell is not barred. If it is determined that thecellBarred IE is not set to ‘notBarred’, the UE assumes at step 2 d-50that its access to the corresponding cell is barred.

FIG. 2E is an exemplary block diagram illustrating an exemplaryconfiguration of a UE according to an embodiment of the presentdisclosure.

The legacy UE and the eLTE UE according to an embodiment of the presentdisclosure may be configured as shown in FIG. 2E.

In reference to FIG. 2E, the UE includes a radio frequency (RF)processor 2 e-10, a baseband processor 2 e-20, a storage unit 2 e-30,and a controller 2 e-40.

The RF processor 2 e-10 has a function for transmitting/receiving asignal over a radio channel such as band conversion and amplification ofthe signal. That is, the RF processor 2 e-10 up-converts a basebandsignal from the baseband processor 2 e-20 to an RF band signal andtransmits the RF signal via an antenna and down-converts the RF signalreceived via the antenna to a baseband signal. For example, the RFprocessor 2 e-10 may include a transmission filter, a reception filter,an amplifier, a mixer, an oscillator, a digital-to-analog converter(DAC), and an analog-to-digital converter (ADC).

Although one antenna is depicted in the drawing, the UE may be providedwith a plurality of antennas. The RF processor 2 e-10 may also include aplurality of RF chains. The RF processor 2 e-10 may perform beamforming.For beamforming, the RF processor 2 e-10 may adjust the phase and sizeof a signal to be transmitted/received by means of the antennas orantenna elements in phase and size. The RF processor 2 e-1—may beconfigured to support a MIMO scheme with which the UE can receivemultiple layers simultaneously

The baseband processor 2 e-20 has a baseband signal-bit stringconversion function according to a physical layer standard of thesystem. For example, in a data transmission mode, the baseband processor2 e-20 performs encoding and modulation on the transmission bit stringto generate complex symbols. In a data reception mode, the basebandprocessor 2 e-20 performs demodulation and decoding on the basebandsignal from the RF processor 2 e-10 to recover the transmitted bitstring. In the case of using an OFDM scheme for data transmission, thebaseband processor 2 e-20 performs encoding and modulation on thetransmission bit string to generate complex symbols, maps the complexsymbols to subcarriers, performs inverse fast Fourier transform (IFFT)on the symbols, and inserts a cyclic prefix (CP) into the symbols togenerate OFDM symbols.

In the data reception mode, the baseband processor 2 e-20 splits thebaseband signal from the RF processor 2 e-10 into OFDM symbols, performsfast Fourier transform (FFT) on the OFDM symbols to recover the signalsmapped to the subcarriers, and performs demodulation and decoding on thesignals to recover the transmitted bit string.

The baseband processor 2 e-20 and the RF processor 2 e-10 process thetransmission and reception signals as described above. Accordingly, thebaseband processor 2 e-20 and the RF processor 2 e-10 may be referred toas a transmitter, a receiver, a transceiver, or a communication unit. Atleast one of the baseband processor 2 e-20 and the RF processor 2 e-10may include a plurality of communication modules for supportingdifferent radio access technologies.

At least one of the baseband processor 2 e-20 and the RF processor 2e-10 may also include multiple communication modules for processing thesignals in different frequency bands. For example, the different radioaccess technologies may include a wireless local area network (WLAN)(e.g., Institute of Electrical and Electronics Engineers (IEEE) 802.11)and a cellular network (e.g., LTE). The different frequency bands mayinclude a super high frequency (SHF) band (e.g., 2.NRHz and NRhz bands)and an mmWave band (e.g., 60 GHz).

The storage unit 2 e-30 stores data such as basic programs for operationof the UE, application programs, and setting information. The storageunit 2 e-30 may also store the information on a second access node forradio communication with a second radio access technology. The storageunit 2 e-30 provides the stored information in response to a requestfrom the controller 2 e-40.

The controller 2 e-40 controls overall operations of the UE. Forexample, the controller 2 e-40 controls the baseband processor 2 e-20and the RF processor 2 e-10 for transmitting and receiving signals. Thecontroller 2 e-40 writes and reads data to and from the storage unit 2e-40. For this purpose, the controller 2 e-40 may include at least oneprocessor. For example, the controller 2 e-40 may include acommunication processor (CP) for controlling communications and anapplication processor (AP) for controlling higher layer programs such asapplications.

FIG. 2F is an exemplary block diagram illustrating an exemplaryconfiguration of a gNB according to an embodiment of the presentdisclosure.

According to an embodiment of the present disclosure, the gNB connectedto at least one of an MME and an NG core may be configured as shown inFIG. 2F. As shown in the drawing, the gNB includes an RF processor 2f-10, a baseband processor 2 f-20, a backhaul communication unit 2 f-30,a storage unit 2 f-40, and a controller 2 f-50.

The RF processor 2 f-10 has a function for transmitting/receiving asignal over a radio channel such as band conversion and amplification ofthe signal. That is, the RF processor 2 f-10 up-converts a basebandsignal from the baseband processor 2 f-20 to an RF band signal andtransmits the RF signal via an antenna and down-converts the RF signalreceived via the antenna to a baseband signal. For example, the RFprocessor 2 f-10 may include a transmission filter, a reception filter,an amplifier, a mixer, an oscillator, a DAC, and an ADC.

Although one antenna is depicted in the drawing, the gNB may be providedwith a plurality of antennas. The RF processor 2 f-10 may also include aplurality of RF chains. The RF processor 1 i-10 may perform beamforming.For beamforming, the RF processor 2 f-10 may adjust the phase and sizeof a signal to be transmitted/received by means of the antennas orantenna elements. The RF processor 2 f-10 may be configured to transmitone or more layers for a downlink MIMO operation.

The baseband processor 2 f-20 has a baseband signal-bit stringconversion function according to a physical layer standard of thesystem. For example, in a data transmission mode, the baseband processor2 f-20 performs encoding and modulation on the transmission bit stringto generate complex symbols. In a data reception mode, the basebandprocessor 2 f-20 performs demodulation and decoding on the basebandsignal from the RF processor 2 f-10 to recover the transmitted bitstring. In the case of using an OFDM scheme for data transmission, thebaseband processor 2 f-20 performs encoding and modulation on thetransmission bit string to generate complex symbols, maps the complexsymbols to subcarriers, performs inverse fast Fourier transform (IFFT)on the symbols, and inserts a cyclic prefix (CP) into the symbols togenerate OFDM symbols.

In the data reception mode, the baseband processor 2 f-20 splits thebaseband signal from the RF processor 2 f-10 into OFDM symbols, performsfast Fourier transform (FFT) on the OFDM symbols to recover the signalsmapped to the subcarriers, and performs demodulation and decoding on thesignals to recover the transmitted bit string. The baseband processor 2f-20 and the RF processor 2 f-10 process the transmission and receptionsignals as described above. Accordingly, the baseband processor 2 f-20and the RF processor 2 f-10 may be referred to as a transmitter, areceiver, a transceiver, or a communication unit.

The backhaul communication unit 2 f-30 provides an interface forcommunication with other nodes in the network. That is, the backhaulcommunication unit 2 f-30 converts a bit string to be transmitted fromthe gNB to another node, e.g., another gNB and core network, to aphysical signal and converts a physical signal received from anothernode to a bit string.

The storage unit 2 f-40 stores data such as basic programs for operationof the gNB, application programs, and setting information. The storageunit 2 f-40 may also store the information on the bearers establishedfor UEs and measurement results reported by the connected UEs. Thestorage unit 2 f-40 may also store the information for use by a UE indetermining whether to enable or disable multi-connectivity. The storageunit 2 f-40 may provide the stored data in reference to a request fromthe controller 2 f-50.

The controller 2 f-50 controls overall operations of the gNB. Forexample, the controller 2 f-50 controls the baseband processor 2 f-20,the RF processor 2 f-10, and the backhaul communication unit 2 f-30 fortransmitting and receiving signals. The controller 2 f-50 writes andreads data to and from the storage unit 2 f-40. For this purpose, thecontroller 2 f-50 may include at least one processor.

As described above, the present disclosure is advantageous in terms ofovercoming a performance limitation caused by UL-DL coverage mismatch insuch a way as to enable a terminal to use a UL frequency for broadercoverage.

Also, the present disclosure is advantageous in terms of preventing alegacy terminal from accessing a next generation mobile communicationnetwork by configuring system information in such a way as to include alegacy IE and a new IE, the system information being broadcast by a basestation.

The methods specified in the claims and specification can be implementedby hardware, software, or a combination of them.

In the case of being implemented in software, it may be possible tostore at least one program (software module) in a computer-readablestorage medium. The at least one program stored in the computer-readablestorage medium may be configured for execution by at least one processorembedded in an electronic device. The at least one program includesinstructions executable by the electronic device to perform the methodsdisclosed in the claims and specifications of the present disclosure.

Such a program (software module or software program) may be stored in anon-volatile memory such as random access memory (RAM) and flash memory,Read Only Memory (ROM), Electrically Erasable Programmable Read OnlyMemory (EEPROM), a magnetic disc storage device, a Compact Disc-ROM(CD-ROM), Digital Versatile Discs (DVDs) or other type of opticalstorage device, and a magnetic cassette. It may also be possible tostore the program in a memory device implemented in combination of partor whole of the aforementioned media. The storage unit may include aplurality of memories.

The program may be stored in an attachable storage device accessiblethrough a communication network implemented as a combination ofInternet, intranet, Local Area Network (LAN), Wireless LAN (WLAN), andStorage Area Network (SAN). The storage device may be attached to thedevice performing the methods according to embodiments of the presentdisclosure by means of an external port. It may also be possible for aseparate storage device installed on a communication network to attachto the device performing the methods according to embodiments of thepresent disclosure.

In the embodiments of the present disclosures, the components aredescribed in singular or plural forms depending on the embodiment.However, the singular and plural forms are selected appropriately forthe proposed situation just for explanatory convenience without anyintention of limiting the present disclosure thereto; thus, the singularform includes the plural form as well, unless the context clearlyindicates otherwise.

Although the description has been made with reference to particularembodiments, the present disclosure can be implemented with variousmodifications without departing from the scope of the presentdisclosure. Thus, the present disclosure is not limited to theparticular embodiments disclosed, and it will include the followingclaims and their equivalents.

Although the present disclosure has been described with variousembodiments, various changes and modifications may be suggested to oneskilled in the art. It is intended that the present disclosure encompasssuch changes and modifications as fall within the scope of the appendedclaims.

What is claimed is:
 1. A method performed by a base station connectedwith at least one of a first core network or a second core network in awireless communication system, the method comprising: generating asystem information block type 1 (SIB 1) message, the SIB 1 messageincluding first information indicating if a cell associated with thebase station is barred for connectivity to the first core network andsecond information indicating if the cell associated with the basestation is barred for connectivity to the second core network;transmitting, to a terminal, the SIB 1 message including the firstinformation and the second information; and receiving, from theterminal, an attach request message for connecting to the second corenetwork, transmitted from the terminal based on the second informationindicating that the cell associated with the base station is not barredfor connectivity to the second core network, wherein a list of publicland mobile networks (PLMNs) for the second core network, included inthe SIB 1 message, is used for an attachment of the terminal to thesecond core network.